Kalinin 4 in late commissioning

Engineers bringing a new reactor into service at the Kalinin nuclear power plant have successfully completed most of their tests. The unit is slated for commercial operation in September.

The operator of all Russia's nuclear power plants, Rosenergoatom, has said that the last of 74 tests in the start-up program was completed successfully on 28 April.

Kalinin 4 key dates:

• First concrete

January 1986

• Work halted

August 1991

• Work restarted

November 2007

• Fuel loading

October 2011

• Criticality

November 2011

The final procedures of this program are required before the unit can be run at its full rated thermal power of 3200 MW, producing 1000 MW of electricity for the grid. They are conducted at the minimum power level and verify the operation of control and protection systems. Some tests concerned the reliability and efficiency of design features such as the removal of heat from the reactor core using natural circulation.

The plant's chief engineer, Igor Bogomolov, said the new reactor unit had "achieved an excellent result." It may now be operated at 50% power for a test period of 72 hours. If all goes well a full-power test period would follow with the intention of putting the unit into commercial operation in September.

Kalinin 4 is a V-320 type VVER pressurized water reactor. The plant is situated in the western Tver region near the town of Udomlya.